ggfacepalm

I can do bare bottom. That's how the tank is right now because one of my axies is still a juvenile and most substrates are too dangerous for him. I was going to do sand once he's older but if the moss does well on bare tanks I'm perfectly fine with that. Thank you so much for all your help.

Thank you! Do you know if java moss can grow on sand or if I'll need something different?

So I'm looking to start planting my tank but I can't seem to find any info on the site here about water temperature requirements for these plants. I have an axolotl tank, so my requirements are cold water (tank is always between 60-62°F), and very low light. The axolotls do not like bright lights at all so I was hoping for something that could do okay with just the light that comes in through the window near the tank and not have to get a grow light and upset the axies. All suggestions and info appreciated. Thanks guys. Edit: It's a 40 gallon tank. I forgot to mention before.